Natural polymers have been used in many pharmaceutical applications and medical device technologies. One natural polymer, chitosan (sometimes referred to herein as CHT), has been used for the preparation of nanoparticles, microspheres, hydrogels, films, fibers, and tablets. Chitosan has been used to prepare potential drug delivery systems such as oral, nasal, parenteral, transdermal and ophthalmic formulations. Chitosan has also been used to prepare wound dressings and tissue sponges (Kumar et al., Chem. Rev. 2004, 104, 6017-6084). However, chitosan formulations and materials suffer from numerous drawbacks including limited stability, biodegradability and tensile strength. Materials such as modified chitosan and synthetic composite materials have been tested for many of the same uses for which chitosan has been evaluated, but many of these materials suffer from similar drawbacks, including insufficient biocompatibility.
Accordingly, there is a need for new materials that are biocompatible and biodegradable, and that have suitable stability and mechanical properties and performance for use in human and other mammalian treatments and therapies. These new materials and compositions would preferably have advantages over chitosan alone, such as additional and/or improved biocompatibility, high stability and improved physical and biological properties. The ability to use these materials as tissue sponges, wound dressings, cosmeceuticals, and/or systems for the delivery of therapeutic agents would further aid researchers in the areas of biomedical engineering, biomaterials, and tissue engineering.